Electrocardiograph bioelectric interface system and method of use

ABSTRACT

A bioelectric interface is disclosed which provides three Einthoven triangle equivalent lead forming electrodes positioned on a subject&#39;s chest so as to provide a Wilson common terminal voltage essentially equivalent to that provided by an Einthoven triangle formed using leads positioned conventionally on a subject&#39;s limbs. Wilson common terminal forming resistors can be of fixed values or variable to allow adjustment of a produced Wilson common terminal voltage. Additional precordial electrodes are also typiclaly present. Electrodes can consist of single elements or groups of electrode elements, and are present in locational regions of the bioelectric interface which allow a single size system to fit to patients with various sized bodies. The electrodes can be of various physical shapes to allow not only direct signal measurement, but also to allow monitoring of high frequency content of signals and to allow enhanced resolution of a region from which measured signals originate. In addition, the present invention bioelectric interface is preferably held in place on a subject&#39;s chest with hydropolymer, and need not be removed to allow cardio-pulmonary-resuscitation, defibrillation, cardiac pacing, electro surgery, electro ablation or impedance cardiography to be performed, and it serves to preserve the relative spatial integrity of the positioning of the electrodes present during use. The presence of a number of spatially separated electrocardiogram system electrodes facilitates reduction of the adverse electrode edge effects when defibrillation is performed through the bioelectric interface.

This Application is a CIP of application Ser. No. 08/434,658 filed May4, 1995, now U.S. Pat. No. 3,678,545.

TECHNICAL FIELD

The present invention relates to systems of electrodes for use inbioelectric interfacing. More particularly, the present invention is asystem, and method of use, which provides all electrodes required byelectrocardiograph systems, including equivalent Einthoven triangle limbelectrodes, on a common subject chest mounted support sheet.

BACKGROUND

Conventional medical analysis and therapy often involves use of aplurality of individual electrodes, each applied independently to anappropriate location on a subject's body by way of electricallyconductive paste, and securing means such as a skin compatible adhesive.A relevant example of use is in the monitoring of Electrocardiogram(ECG) signals at precordial; and at left and right arm, and left Leglocations by independent electrodes in an Einthoven triangleconfiguration.

Further, it is known to apply individual non-invasive precordialelectrodes to a subject's chest to allow not only the acquiring of ECGdata, but to allow defibrillation of fibrillating hearts and to allowthe pacing of arrested hearts and the like.

A problem which presents in the use of such independent electrodes,however, is that reliable, repeatable placement upon a subject's body isdifficult. For instance, it is generally accepted that a majority of theerrors encountered in acquiring ECG data is caused by improper electrodeplacement by medical technical staff.

Of relatively recent development are flexible electrode pads whichcomprise a multiplicity of electrodes affixed thereto in an appropriatepattern for use in medical analysis and/or therapy. For instance, aPatent to Manoli, U.S. Pat. No. 4,583,549 describes an ECG electrode padin which six conductive discs are plated and etched on a flexibleadhesive pad in a clinically conventional predetermined patterneffective for precordial ECG electrode placement. Reproducibleattachment of said six electrodes to a subject's chest in the properarrangement for use with standard ECG machines is thus made possible bya single application of an electrode pad of an appropriate size for usewith any subject. However, it would seem that the Manoli system wouldrequire a host of numerous sized electrode pads to accommodate subjectsof different sizes as the Claims recite rather strict electrodeplacement criteria which are referenced with respect to a subject'sbody. A single electrode pad would not meet said requirements onsubjects of different sizes. A Patent, U.S. Pat. No. 4,121,575 to Millset al. describes a multiple electrode device for application to asubject's chest, formed in stretchable non-conductive material havingapertures in the V1-V6 positions. The capability for stretching thematerial is held to allow accurate positioning of V1-V6 electrodes onsubjects of differing body size. A Patent to Groeger et al., U.S. Pat.No. 4,957,109 describes an electrode assembly comprising right and leftarm and leg leads, and precordial leads all affixed to a commonstructure. The arm and leg leads do not affix to a subject's chestduring use. The Mills et al. and Groeger et al. systems do not serve tomaintain a relatively fixed positioning of electrodes therein duringuse, and it is noted that movement between electrodes during usefrequently causes confounding noise generation in electrocardiographysystems. Another Patent, U.S. Pat. No. 5,327,888 to Imran describes aprecordial electrode strip which is supplied with detachable RA, LA andLL limb leads, which detachable limb leads are applied to subject limbsin use.

Patents to Way et al., U.S. Pat. Nos. 4,955,381 and 5,080,099 describemultiple conductive polymer pad containing electrodes for performingmultiple electrical physiological functions from a set of electrodeswith respect to a subject, at or about the same time, such asdefibrillation, pacing and monitoring. Other Patents which disclosemultiple electrode assemblies are U.S. Pat. No. 4,328,814 to Arkans andU.S. Pat. No. 5,191,886 to Paeth et al. These Patents each describe aplurality of electrodes configured in a physically seriesedconfiguration with conductive leads to various physically seriesedcontacts, present at one end thereof. In addition, a Patent to Collins,U.S. Pat. No. 3,612,061 describes a porous sheet of elastic materialwhich supports an array of electrodes adapted to contact a wearer'sskin, and U.S. Pat. No. 5,184,620 to Cudahy et al. describes anelectrode pad system comprised of a multiplicity of electrodes which areutilized in defibrillation and pacing scenarios as directed by anon-line computer driven analysis and electrical energy applicationsystem, which system distributes electrical energy to appropriate setsof said multiplicity electrodes in response to subject needs.

Continuing, it is to be understood that particularly appropriatematerials in which to form an electrode pad with a plurality of ECGmonitoring electrodes present therein are hydropolymers. This is becausehydropolymers can be pliable, self-adhesive and compatible withmaintaining the requisite hydration of subject skin to which they affixduring prolonged use. The pliable property makes hydropolymersexceptionally well suited for application to unpredictableirregularities of various subject's chests and the self-adhesiveproperty negates the need to apply adhesive material to affix thepresent invention to a subject's body during use. As well, the need toapply electrically conductive paste to electrically conducting areas ofelectrodes becomes unnecessary.

A Patent, U.S. Pat. No. 5,331,959 to Imran, describes a low impedancedry conforming contact member in which are present rods or filamentswhich are cured into material such as a silicon-based material, suchthat when configured as an electrode provide impedance reducingprojections which protrude into the pores of a subject's skin duringuse. Said rods or filaments reduce the need to use conductive paste.Another U.S. Pat. No. 4,524,087 to Engel, describes a conductiveelectrode application comprising an adhesive, swellable,dermally-nonirritating, conformable, ionic hydropolymer biomedicalelectrode fabricated by a claimed process.

Continuing, three Patents to Keusch et al, U.S. Pat. Nos. 4,706,680,4,989,607 and 5,143,071 describe hydrogels which are caused to be highlyconductive by the inclusion of an essentially uniformly distributedactive electrolyte therein. Said Patents state that to form thehydrogels a polymeric mixture is caused to become cross-linked byexposure to radiant energy. This causes a gel-like solid to form whichis sufficiently tacky and adhesive to adhere to subject's skin and whichis substantially non-stringy and non-aggressive so that subject comfortis protected.

A Patent to Highe et al., U.S. Pat. No. 5,289,822 describes an electrodeformed of a dry-conductive material having an outer surface forplacement in contact with a subject's skin. A composition is depositedon at least a portion of the surface of the dry-electrode whichcomprises a plurality of water-containing vesicles. The purpose of saidwater-containing vesicles being to effect an immediate lowering ofsubject skin resistance upon the application of the electrode. It isstated that a period of approximately four minutes is otherwise requiredfor moisture from a subject's skin to naturally occur at the electrode.

A Patent to Schmid, U.S. Pat. No. 5,124,107 describes a process formanufacturing a body electrode which comprises one or more galvanicallyactive sensors which are combined with a first layer capable of adheringto a subject's skin, on a body contact side thereof. A second coveringor supporting layer is also present on the opposite side of the bodyelectrode. The process for manufacture provides that the two layers aresequentially cast in a mold which provides intended shape and size. Theprocedure avoids manufacturing problems encountered where electrodes arestamped from a preformed sheet. A potential problem of using such anelectrode as provided by the Schmid 107 Patent is that it provides alaterally oriented conductive path between said galvanically activesensors through the first layer thereof. Electrically anisotropicconducting hydropolymers would be preferable.

Continuing, a Patent to Suyama et al, U.S. Pat. No. 5,132,058 describesa process for producing an anisotropically electroconductive sheethaving a plurality of electroconductive portions extending in thedirection of the thickness of the sheet. Application of an anisotropicmagnetic field is utilized to draw electroconductive particles into amolding material such that said electroconductive particles gather wheresaid electromagnetic field is applied. Another Patent which describes asimilar system to that achieved by practice of the Suyama et al. Patentis U.S. Pat. No. 4,778,635 to Hechtman et al. A Patent to Kashiro etal., U.S. Pat. No. 4,209,481 describes an anisotropicallyelectroconductive sheet in which electroconductive wires are formed intopatterned groupings, which patterned groupings are in turn formed intopatterns. The wires are parallel in the direction of the sheetthickness, and spaced apart by non-electroconductive elastomer. AnotherPatent, U.S. Pat. No. 5,045,249 to Jin et al., describes electricalinterconnections made by means of a layer or sheet medium comprisingchains of magnetically aligned, electrically conductive particles in anonconducting medium. End particles of chains protrude from a surface ofthe medium to effect electrical contact. A Patent to Abraham et al.describes an electrode for use with electrosurgical apparatus whichprovides capacitive coupling with the skin of a subject. The electrodeincludes a conductive plate connected to the electrosurgical apparatuswith an insulating layer disposed in contact with the conductive plateand on the opposite face of the insulator there is provided conductivematerial in the form of a plurality of discrete islands of conductiveadhesive material which contact the skin of a subject during use.Another Patent, U.S. Pat. No. 5,232,639 to Reitz et al. describes aprocess for forming articles with anisotropic void distributionstherein.

It is also established that electrode configuration can be important indetermining the accuracy of monitored signals. For instance, the use ofa Bulls-eye shaped electrode, which comprises a central electrodesurrounded by one or more annular ring electrodes, can provide signalswhich focus upon a specific region of a subject's heart, which focus isnot available when a simple electrode geometry is utilized. As well,Bulls-eye shaped electrodes allow determination of derivatives ofdetected signals in use.

An article by He et al. titled "Body Surface Laplacian Mapping ofCardiac Electrical Activity" published in The American J. of Cardiology,Vol. 70, Dec. 15, 1992 describes the use of Bulls-eye shaped electrodesto map derivatives of cardiogenic signals.

Patents which describe unusual geometrical electrode configurations are,for instance, a Patent to Clare et al., U.S. Pat. No. 5,295,482 whichdiscloses a large surface area electrode in which a central portion issurrounded by two surrounding ring portions., said central and twosurrounding ring portions being separated from one another by annularregions. This Patent states that during use current density is found tobe greater at the outer edge of an electrode than it is at a morecentral location. The purpose of the described system is disclosed asbeing to effect a more uniform distribution of current density over theeffective large surface area of the disclosed electrode during use, byproviding multiple "outer-edge" providing portions. Other referenceswhich describe the "edge-effect" are a Patent to Dahl et al., U.S. Pat.No. 5,063,932 and a Canadian Patent No. 1,219,642. In addition, twoarticles also treat the subject, said articles being: "Optimal ElectrodeDesigns for Electrosurgery, Defibrillation, and External CardiacPacing", by Kim et al., which appeared in Transactions On BiomedicalEngineering, Vol. BME-33, No. 9, September 1986; and "Analysis andControl of the Dispersive Current Distribution under Circular DispersiveElectrodes", by Wiley and Webster, which appeared in the IEEETransactions On Biomedical Engineering, Vol. BME-29, No. 5, in May 1982.

Even in view of the above cited literature, need remains for aconvenient to utilize bioelectric interface which is suitable forapplication to subjects of differing body sizes, which bioelectricinterface comprises equivalent Einthoven triangle limb electrodes on acommon subject chest mounted support sheet, which preferably comprisesan electrically anisotropic conducting hydropolymer self adhesivematerial, which provides electrodes of a geometry appropriate foroptimizing electrical contact to a subject, which allows accuratelymonitored signals to be obtained therefrom during use, and whichfacilitates external cardiac pacing, cardiac defibrillation, electrosurgery, electro-ablation processes, and impedance cardiography.

DISCLOSURE OF THE INVENTION

The present invention concerns the practice of electrocardiographywherein a number of electrical signals, which are diagnostic ofmyocardial function, are acquired via electrodes placed upon a subject'sbody. As regards this use, subject contacting electrodes can bespatially oriented in lead configurations such as Einthoven triangle,Frank, McFee, Schmidt, twelve-lead configurations etc., and in arraypatterns for use in mapping, etc. The present invention bioelectricinterface is a system which provides Right-Arm (RA), Left-Arm (LA) andLeft-Leg (LL) electrodes which form, when applied to a subject's chestin use, an Einthoven frontal lead triangle with an equivalent I, II, IIIlead pattern, said pattern being determined as acceptable bypresentation of a voltage with respect to ground at a formed Wilsoncommon terminal, which voltage with respect to ground is within aselected range of deviation from a voltage with respect to groundpresented at a conventionally formed Wilson common terminal usingconventional subject limb positioning of RA, LA and LL electrodes. Thepresent invention bioelectric interface further provides all necessaryelectrodes, appropriately configured for mounting to a subject's chest,for use with electrocardiograph systems.

As demonstrated in the Background Section of this Disclosure, multipleelectrode systems are not unknown. However, said known systems do notprovide all electrodes for use with a twelve-lead electrocardiogram(ECG) system conveniently positioned on a bioelectric interface whichcan be easily, accurately and repeatably applied to a subject's chest ina desired anatomical orientation. A twelve-lead (ECG) system, byconventional practice, requires that electrodes be placed on a subject'sRight (RA) and Left (LA) arms and Left leg (LL), and that six precordialelectrodes (V1, V2, V3, V4, V5, and V6), be placed upon the subject'schest. The locations of the V1-V6 electrodes are:

V1--in the region of the fourth intercostal space at the right sternalborder;

V2--in the region of fourth intercostal space at the left sternalborder;

V4--in the region of fifth intercostal space at the left mid-clavicularline;

V3--in the region of the midpoint between the V2 and V4 electrodes;

V5--in the region of the fifth intercostal space at the left anterioraxillary line;

V6--in the region of the fifth intercostal space in the leftmid-axillary line.

No known reference, however, suggests that arm and leg equivalentelectrodes should be placed at chest locations relatively near theprecordial electrodes. The present invention teaches that said arm andleg equivalent electrodes are to be so placed. The location of said armand leg equivalent electrodes is best understood by reference to theDrawings which are discussed in the Detailed Description of thisDisclosure, however, verbally their positioning can be generallydescribed as:

Right Arm--generally in the region of the second intercostal space tothe right of the sternum;

Left Arm--generally in the region of left fourth intercostal space inthe mid-axillary line; and

Left Leg---generally in the region of the inferior costal margin in theleft mid-clavicular line.

In addition, the present invention teaches the optional use of multipleelectrode element electrodes, (eg. "Bulls-eye" shaped electrodes), forinstance, in a multiple electrode element electrode system. Use ofsingle electrode element "Button" electrodes is conventional, and in useeach such Button electrode serves to measure an electrical signalbetween it and a common or reference electrode, (typically termeduni-polar electrodes), or a similar button electrode (typically termedBi-polar electrodes). When multiple electrode element (eg. Bulls-eye),electrodes are utilized, however, signals are generated between twocomponents of a single electrode. Continuing, a Bulls-eye shapedelectrode is typically configured like a "target". That is, typically aButton electrode will be centrally located within an outer annularshaped electrode. The benefits provided by such multi-electrode elementelectrodes are the ability to achieve greater resolution of signalsgenerated in a specific area of a subject's heart, and it is noted, thatthe signals measured are representative of the derivatives of electricalsignal activity produced by a subject's heart. That is, the signalprovided between a Button and First Annulus is proportional to aderivative of a signal generated by a subject's heart. Additionalannular ring electrodes can also be present and signals measured therebyare proportional to higher order derivatives. Use of "Bulls-eye"electrode geometry then allows investigation of High Frequency aspectsof electrical activity generated by a subject's heart. It is noted thata limitation is associated with the use of Bulls-eye electrodes in thatthe smaller they are dimensioned, although enabling increased resolutionand investigation of electrical signals generated in smaller regions ina heart, the smaller the magnitude of signal they provide. In a multipleelectrode setting then, where relative motion between electrodes cancreate confounding electrical noise, it then becomes increasinglyimportant to prevent relative motion between electrodes and componentsof Bulls-eye electrodes, when Bulls-eye electrodes are present. (Note,it is emphasized that it is possible to achieve a result similar to thatprovided by "Bulls-eye" electrodes with other multiple elementelectrodes, and for the purposes of this Disclosure any functionallysimilar electrode is to be considered as included by the terminology"Bulls-eye" whether a closed annulus is present or not).

It is also to be understood that a present invention electrode canconsist of a plurality of electrode elements, (eg. a plurality of buttonshaped electrode elements), configured in a region of the bioelectricinterface which, in use, aligns with an anatomical location appropriatefor use in a twelve-lead (ECG) system.

With the forgoing in mind, it is then to be appreciated that the systemof the present invention is a bioelectric interface comprised of aplurality of electrodes which are affixed to a support sheet in adesired spatially separated pattern, such that in use said electrodesare essentially fixed in location with respect to one another. It isnoted that fixing said relative position between electrodes, and betweenelectrode elements, serves to reduce electrical noise which can begenerated when, in use, electrodes move with respect to one another.Again, it is to be understood that the electrodes can be of singleelectrode element, or multiple electrode element Button or Bulls-eye,(or other), geometry.

Continuing, a typical present invention bioelectric interface has anadhesive material present over at least a portion of a surface thereofwhich contacts a subject in use. The adhesive material of the presentinvention can have the properties of simultaneously demonstratingessentially electrically anisotropicity, but isotropic mechanical (eg.pliability and adhesion), properties. That is, the specific impedanceacross the adhesive material can be significantly different from thatlaterally directed, but the mechanical properties such as adhesion andpliability are typically essentially consistent. (Note, the term"specific impedance" is used to refer to the regional bulk property ofthe adhesive material, rather than properties resulting from dimensionsof sheets fabricated therefrom). In the preferred embodiment, theadhesive material is a hydropolymer sheet which demonstrates a tackinesson a subject skin contact side thereof. Hydropolymers are particularlyapplicable in realization of the present invention as they areelectrically conductive, relatively nonirritating to a subject's skin,and they demonstrate excellent adhesive qualities. Commerciallyavailable hydropolymer sheets with isotropic electrical properties, areavailable from Promeon of Boston, Mass. under the product designationRG-60 Series Hydrogels. Lec-Tec of Minneapolis, Minn. also marketshydrogels. The present invention provides that such adhesivehydropolymer sheet material can be utilized, if "slits" are enteredthereto at appropriate locations to effect electrical anisotropicitybetween electrodes present at various laterally offset locations. It isnoted that hydropolymer sheets do not typically demonstrate a rigiditysufficient to maintain a spatially stable relationship betweenelectrodes affixed thereto, but particularly when slits are formedtherein, hence, the present invention requires that a support sheetcarrier matrix be present to which electrodes and said adhesive sheetattach. That is, the system of the present invention will then comprisea support sheet carrier matrix to which are attached, at desiredspatially offset locations, electrodes, over which configuration saidhydropolymer is placed so that said electrodes are sandwiched betweensaid carrier matrix and hydropolymer. At locations between the variouselectrodes said "slits" are then caused to be present by, typically, amechanical process. It is noted that in practice said slits need not beof a degree to provide complete discontinuity between various regions ofthe resulting hydropolymer system to provide a sufficiently anisotropicspecific impedance system. The Background Section also identifiesvarious electrically anisotropic adhesive materials. The presentinvention, in addition, teaches that an essentially electricallyanisotropic adhesive material sheet can be provided by a "Scrim"material comprising a number of channels therethrough, which channelsare caused to be filled with an electrically conductive adhesivematerial, (preferably a hydropolymer), such that "island channels" ofconductive material exist across the resultant sheet, but such thatelectrically nonconductive scrim exists between laterally orientedislands of conductive material. The "Scrim" can be electricallyconductive carbon fibers, and/or electrically non-conducting plasticfilaments, as required to provide a desired electrical anisotropicity.

Continuing, the present invention, in its preferred embodiment, teachesthat one size of multiple electrode bioelectrical interface should besufficient for use with all subjects, regardless of body size. Thepresent invention teaches that to accomplish placement of electrodes,such as defined infra for twelve-lead systems, on subject's bodies ofvarious size, that groups of electrode elements should be available inthe region of for instance, the fourth intercostal space at the rightsternal border, (ie. the location for a V1 lead). In use then,regardless of a subject body size, one electrode element in a group ofelectrode elements in the region of the fourth intercostal space at theright sternal border, will provide an optimum result. Which electrodeelement in a group of electrode elements provides said optimum result,will of course be subject specific. Prior art has failed to recognizethe need to provide a group of electrode elements in the region of aspecific electrode placement location so that a user can select,manually or automatically, an appropriately placed electrode element fora specific subject.

It is also noted that as the relative spatial separation of variouselectrodes is essentially fixed by the present invention, and as theirposition on a subject's body is typically secured by an adhesive sheet,it is possible to conduct activities such ascardio-pulmonary-resuscitation (CPR) on a subject to which the presentinvention bioelectric interface is applied, without removal thereof.Such is essentially impossible where individual leads are utilized in an(ECG) system. As well, the present invention teaches that the means formaking electrical contact to the electrodes should be available on theouter, non-subject contact, surface of the bioelectrical interface. Forinstance, snaps might be provided so that leads from any (ECG) systemcan easily attach thereto, or so that conductive tracks can be employedto bring signals to a manifold or connector means for convenientelectrical access.

It is also emphasized that the electrodes in the bioelectric interface,being electrically conductive, enable, in an emergency, the applicationof defibrillation paddle-type electrodes to said interface means formaking intimate electrical contact to said electrodes without removingthe present invention bioelectrical interface from the subject. And,because the present invention is firmly affixed to a subject, thedefibrillation shock will be safely transmitted to the subject withlittle, or no attenuation. It is also emphasized that in use, first andsecond conventional paddles of a defibrillation system can be caused tocontact first and second spatially separated groups of electrodes in thebioelectric interface, press contacted electrodes into good electricalcontact with the subject, and deliver electrical defibrillating pulseenergy therethrough. Further, the presence of multiple electrodes, (andeven multiple electrode elements within an electrode), within adefibrillation paddle-sized cluster of electrodes, through whichdefibrillation electrical energy can be delivered to a subject, serve toreduce adverse edge effects associated with applying defibrillationelectrical energy through single element paddle, (or pad), electrodes.Special electrodes can be specifically designed which serve to reduceedge effects, and use thereof in the present invention Bio-electricinterface is within the scope of the present invention.

One can also utilize one or more electrodes in the present inventionbioelectric interface for heart pacing, electrosurgery, electro ablationand impedance cardiography.

The present invention bioelectric interface can be better described, inits most basic form, as comprising a support sheet in functionalcombination with at least three (3) spatially separatedelectrocardiogram system electrodes, with each of said at least three(3) spatially separated electrocardiogram system electrodes being asingle electrical electrode element or a group of electricallyindependent electrode elements. Each of said spatially separatedelectrocardiogram system electrodes is affixed to said support sheet ina manner such that the relative positions of said electrocardiogramsystem electrodes with respect to one another are essentially fixedtherewithin. Three (3) of said at least three (3) electrocardiogramsystem electrodes being configured in an RA, LA, LL electrocardiogramsystem electrode pattern. The positioning of said three (3)electrocardiogram system electrodes as applied to a subject's chestduring use can be described as follows:

electrode RA being generally in the region of the second intercostalspace to the right of the sternum;

electrode LA being generally in the region of the left fourthintercostal space in the mid-axillary line;

electrode LL being generally in the region of the inferior costal marginin the left mid-clavicular line;

Further, said electrodes RA, LA and LL form, when applied to a subject'sbody in use, an Einthoven frontal lead triangle with an equivalent I,II, III lead pattern which is determined as acceptable by presentationof a voltage with respect to ground at a formed Wilson common terminal,which voltage with respect to ground is within a selected range ofdeviation from a voltage with respect to ground presented at aconventionally formed Wilson common terminal using conventional subjectlimb positioning of RA, LA and LL electrodes. Said user selected rangeof voltage deviation can be selected to be less than one (1.0)millivolt, one (1.0) millivolt, or greater than one (1.0) millivolt.

The present invention bioelectric interface can further comprise anequivalent electrocardiogram system RL electrode, and said RA, LA, LLand RL electrodes can be present in the support sheet such thatperforations allow easy detachment of said equivalent electrocardiogramRA, LA, LL and RL electrodes, in use, thereby allowing them to beautomatically positioned at a location in contact with a subject'schest, or by manual manipulation, in conventional subject limbpositions.

The present invention bioelectric interface support sheet is typicallyat least partially covered with an adhesive material on a subjectcontacting side thereof, and said adhesive material can present withelectrical conductive properties which can be isotropic, or regionallyanisotropic such that the specific impedance through said adhesivematerial is less that in a laterally oriented direction. Said regionalanisotropic electrical conductive properties of said adhesive materialcan be effected, as described infra herein, by the presence of anelectrically conductive and/or nonconductive scrim patterned therein soas to form channel regions of electrically conductive adhesive materialthrough said adhesive material bordered by said scrim material, suchthat adhesive material in one channel region does not contact that inother regions. An alternative approach to effecting said regionalanisotropic electrical conductive properties of the adhesive materialinvolves the placing of slits therein. Said adhesive material can be ahydropolymer and it can be caused to cover essentially the entiresubject contacting surface of said support sheet.

As mentioned, at least one of said spatially separated electrocardiogramsystem electrodes can be of a construction consisting of a group ofelectrically independent electrode elements, and said elements can beconfigured in, for instance, Bulls-eye and multiple button shapedelectrode elements patterns.

A method of providing an Einthoven triangle equivalent RA, LA, LLpattern of electrodes on the chest of a subject, utilizing the presentinvention bioelectric interface, can comprise the steps of:

a. Providing a present invention bioelectric interface comprising asupport sheet in functional combination with at least three (3)spatially separated electrocardiogram system electrodes as alreadydescribed, wherein at least one (1) of said at least three (3) spatiallyseparated electrocardiogram system electrodes is of a constructionconsisting of a group of electrically independent electrode elements. Asdescribed above, each of said spatially separated electrocardiogramsystem electrodes is affixed to said support sheet in a manner such therelative positions of said electrocardiogram system electrodes withrespect to one another are essentially fixed therewithin. Three (3) ofsaid at least three (3) electrocardiogram system electrodes areconfigured in an RA, LA, LL electrocardiogram system electrode pattern,such that said three (3) electrocardiogram system electrodes are appliedon a subject's chest during use as follows:

electrode RA being generally in the region of the second intercostalspace to the right of the sternum;

electrode LA being generally in the region of the left fourthintercostal space in the mid-axillary line;

electrode LL being generally in the region of the inferior costal marginin the left mid-clavicular line;

Also as described above, said electrodes RA, LA and LL form, whenapplied to a subject's body in use, an Einthoven frontal lead trianglewith an equivalent I, II, III lead pattern which is determined asacceptable by presentation of a voltage with respect to ground at aformed Wilson common terminal, which voltage with respect to ground iswithin a selected range of deviation from a voltage with respect toground presented at a conventionally formed Wilson common terminal usingconventional subject limb positioning of RA, LA and LL electrodes. Saiduser selected range of voltage deviation can be selected to be less thanone (1.0) millivolt, one (1.0) millivolt, or greater than one (1.0)millivolt;

b. Applying said bioelectric interface to a subject;

c. Selecting at least one electrically independent element in each ofsaid at least one electrocardiogram system RA, LA and LL electrode(s)consisting of a group of electrically independent electrode elements;

d. Connecting said selected electrocardiogram system electricallyindependent element(s) in each of said RA, LA and LL electrode(s) toappropriate inputs of an electrocardiogram system.

Continuing, a preferred embodiment of the present invention bioelectricinterface comprises a support sheet in functional combination with atleast nine (9) spatially separated electrocardiogram system electrodes.Each of said at least nine (9) spatially separated electrocardiogramsystem electrodes being a single electrical electrode element or a groupof electrically independent electrode elements. Each of said spatiallyseparated electrocardiogram system electrodes is affixed to said supportsheet in a manner such the relative positions of said electrocardiogramsystem electrodes with respect to one another are essentially fixedtherewithin, with nine (9) of said at least nine (9) electrocardiogramsystem electrodes being configured in an RA, LA, LL, V1, V2, V3, V4, V5,V6 electrocardiogram system electrode pattern. In use, said nine (9)electrocardiogram system electrodes are applied to a subject's chestduring use as follows:

electrode RA being generally in the region of the second intercostalspace to the right of the sternum;

electrode LA being generally in the region of the left fourthintercostal space in the mid-axillary line;

electrode LL being generally in the region of the inferior costal marginin the left mid-clavicular line;

Said electrodes RA, LA and LL form, as described infra herein, whenapplied to a subject's body in use, an Einthoven frontal lead trianglewith an equivalent I, II, III lead pattern which is determined asacceptable by presentation of a voltage with respect to ground at aformed Wilson common terminal, which voltage with respect to ground iswithin a selected range of deviation from a voltage with respect toground presented at a conventionally formed Wilson common terminal usingconventional subject limb positioning of RA, LA and LL electrodes. Saiduser selected range of voltage deviation can be selected to be less thanone (1.0) millivolt, one (1.0) millivolt, or greater than one (1.0)millivolt.

The V1, V2, V3, V4, V5, V6 electrocardiogram system precordial electrodepattern is formed as:

electrode V1 in the region of the fourth intercostal space at the rightsternal border;

electrode V2 in the region of the fourth intercostal space at the leftsternal border;

electrode V4 in the region of the fifth intercostal space at the leftmid-clavicular line;

electrode V3 in the region of the midpoint between electrode groups V2and V4;

electrode V5 in the region of the fifth intercostal space in the leftanterior axillary line; and

electrode V6 in the region of the fifth intercostal space in the leftmid-axillary line.

The described preferred embodiment of the present invention can alsofurther comprise an equivalent electrocardiogram system RL electrode,and perforations can be present in said support sheet to allow easydetachment and deployment of said equivalent electrocardiogram RA, LA,LL and RL electrodes, in use, so that they can be positioned in contactwith a subject's chest, or in conventional subject limb position.

As described above, the presently described present inventionbioelectric interface support sheet is also typically at least partiallycovered with an adhesive material on a subject contacting side thereof,which adhesive material presents with electrical conductive propertieswhich can be isotropic or regionally anisotropic such that the specificimpedance through said adhesive material is less than that in alaterally oriented direction. As also already discussed, a preferredadhesive material is hydropolymer which covers essentially the entiresubject contacting surface of said support sheet.

Also as discussed above, each of the electrodes can be of a constructionconsisting of a group of electrically independent electrode elements,such as a Bulls-eye pattern, and multiple button shaped electrodeelements.

A method of acquiring electrocardiographic data can comprise the stepsof:

a. Providing a bioelectric interface comprising a support sheet infunctional combination with at least nine (9) spatially separatedelectrocardiogram system electrodes, as just described;

b. Affixing said bioelectric interface to a subject as described above,and causing electrodes therein to be electrically attached to anelectrocardiographic system such that familiar electrocardiographic datais obtained.

Said method of acquiring electrocardiographic data said method ofacquiring electrocardiographic data can further include the step ofremoving and deploying said electrodes RA, LA and LL configured in anEinthoven frontal triangle equivalent LA, RA, LL pattern, utilizingperforations in said support sheet, and affixing said RA, LA and LLelectrodes to conventional subject limb locations.

A method of utilizing any present invention bioelectric interface duringformation of an Einthoven triangle equivalent or during acquisition ofelectrocardiographic data, can further comprise the simultaneous step ofperforming a procedure selected from the group consisting of;

a. cardio-pulmonary resuscitation

b. cardiac defibrillation;

c. cardiac pacing;

d. electro surgery;

e. electro-ablation; and

f. impedance cardiography.

on said subject without removing said bioelectric interface.

Where defibrillation is performed, two conventional defibrillationpaddles are positioned so that a first conventional defibrillationpaddle contacts at least two of said electrocardiogram systemelectrodes, and a second said conventional defibrillation paddlescontacts at least two of said electrocardiogram system electrodes, saidtwo at least electrodes contacted by said first conventionaldefibrillation paddle being different than, and spatially separatedfrom, said at least two electrodes contacted by said second conventionaldefibrillation paddle. In use, electrodes contacted by defibrillationpaddles are caused to be pressed firmly into good contact with asubject. The result of the presence of multiple electrodes being thatdefibrillation pulse current distribution electrode edge effects arereduced.

It is further noted that the voltage present at a formed Wilson commonterminal can be a root-mean-square value of a selected portion of asubject electrocardiogram system monitored electrocardiogram cycle, suchas the QRS complex.

Finally, it is noted that a conventional Wilson common terminal is acentral "Y" interconnection point of fixed value, (eg. 10,000 ohm),resistors attached to RA, LA and LL electrodes. The present inventionprovides that at least one of said resistors can be variable and can, inuse, be adjusted and thereby set a Wilson common terminal voltageproduced by use of a present invention Bioelectric Interface, to adesired value. The application of variable resistors in forming a Wilsoncommon terminal in combination with a present invention BioelectricInterface, to effect production of a Wilson common terminal voltagewhich is within a desired deviation value with respect to a similarvoltage which would be obtained utilizing conventional limb positionedelectrodes, is not, to the inventor's knowledge, obviated in any knownrerference or combination of references.

The present invention will be better understood by reference to theDetailed Description Section in conjunction with the accompanyingDrawings.

SUMMARY OF THE INVENTION

It is a primary purpose of the present invention to teach thatelectrodes configured in an RA, LA, LL electrocardiogram systemelectrode pattern in a bio-electric interface should be applied to asubject's chest during use, the positioning of said electrocardiogramsystem electrodes being:

electrode RA being generally in the region of the second intercostalspace to the right of the sternum;

electrode LA being generally in the region of the left fourthintercostal space at the mid-axillary line;

electrode LL being generally in the region of the inferior costal marginin the left mid-clavicular line;

said electrodes RA, LA and LL forming an Einthoven frontal lead trianglewith an equivalent I, II, III lead pattern which is determined asacceptable by presentation of a voltage with respect to ground at aformed Wilson common terminal, which voltage with respect to ground iswithin a selected range of deviation from a-voltage with respect toground presented at a conventionally formed Wilson common terminal usingconventional subject limb positioning of RA, LA and LL electrodes. (Saiduser selected range of voltage deviation can be selected to be less thanone (1.0) millivolt, one (1.0) millivolt, or greater than one (1.0)millivolt).

It is another purpose of the present invention to teach that sixprecordial electrodes (V1, V2, V3, V4, V5, and V6) in said bioelectricinterface, should also be placed upon the subject's chest in combinationwith said RA, LA and LL electrodes. The locations of the V1-V6electrodes being:

V1--in the region of the fourth intercostal space at the right sternalborder;

V2--in the region of fourth intercostal space at the left sternalborder;

V4--in the region of fifth intercostal space at the left mid-clavicularline;

V3--in the region of the midpoint between the V2 and V4 electrodes;

V5--in the region of the fifth intercostal space at the left anterioraxillary line;

V6--in the region of the fifth intercostal space in the leftmid-axillary line.

It is yet another purpose of the present invention to teach the use ofmultiple electrode element electrodes, (eg. "Bulls-eye" shapedelectrodes), as well as single electrode element "Button" electrodes ina bioelectric interface.

It is still yet another purpose of the present invention to teach abioelectric interface which has an adhesive material present over atleast a portion of a surface thereof which contacts a subject in use.

It is yet still another purpose of the present invention to teach abioelectric interface in which the adhesive material is a hydropolymer.

It is another purpose of the present invention to teach a bioelectricinterface in which the adhesive material demonstrates anisotropicspecific impedance.

It is yet another purpose of the present invention to teach a method ofutilizing any present invention bioelectric interface during formationof an Ehintoven triangle equivalent or during acquisition ofelectrocardiographic data, which further comprises the simultaneous stepof performing a procedure selected from the group consisting of;

a. cardio-pulmonary resuscitation

b. cardiac defibrillation;

c. cardiac pacing;

d. electro surgery;

e. electro-ablation; and

f. impedance cardiography.

on said subject without removing said bioelectric interface.

It is still yet another purpose of the present invention to teach abioelectric interface comprised of a plurality of electrodes which areaffixed to a support sheet in a desired spatially separated pattern,such that in use said electrodes are essentially fixed in location withrespect to one another such that confounding noise signals resultingfrom relative motion between said electrodes are reduced in use.

It is another purpose of the present invention to teach the use ofvariable resistor(s) in formation of a Wilson common terminal. Thepurpose thereof being to allow adjustment of a voltage appearing at aWilson common terminal formed utilizing present invention BioelectricInterface RA, LA and LL electrodes, so that it is within a desired rangeof deviation from a Wilson common terminal voltage obtained utilizingconventionally placed limb electrodes.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1a shows a side elevational view of a bioelectric interface showingan electrode "sandwiched" by an adhesive sheet and a carrier matrix.

FIG. 1b shows a side elevational view of two electrodes situated on anadhesive sheet in essentially fixed relative positions with respect toone another.

FIG. 2 shows a view of a two electrode bioelectric interface with acommon adhesive sheet applied thereto, in which common adhesive sheet ispresent an electrically anisotropic property causing slit presentbetween.

FIGS. 3a and 3b show top and side elevation views respectively of anovel electrically anisotropic adhesive sheet.

FIGS. 4a and 4b show various designs for electrodes.

FIG. 4c shows the electrodes of FIGS. 4a and 4b sandwiched between acarrier matrix and an adhesive sheet.

FIG. 5a shows a multi-element electrode configured in a Bulls-eyepattern.

FIG. 5b shows a multi-element electrode pattern configured from buttonelectrodes.

FIG. 6a shows a partial frontal view of a human torso, with formation ofa Wilson Common Terminal from standard RA, LA and LL electrodesindicated.

FIG. 6b shows a partial frontal view of a human torso, with formation ofan equivalent Wilson Common Terminal indicated, as formed fromequivalent RA, LA and LL electrodes of the present invention bioelectricinterface.

FIG. 7a shows a bioelectric interface configured for use with a twelvelead (ECG) system. Shown are groups of electrodes which serve to allow a"one-size-fits-all" result. Also shown is an exemplary presence of amulti-element Bulls-eye electrode, and the presence of "slits" in anadhesive sheet to effect electrical anisotropic properties therein.

FIG. 7b shows a bioelectric interface configured for use with a twelvelead (ECG) system. Shown are groups of electrodes made of a plurality ofelectrode elements as shown in FIG. 5b, which serve to allow a"one-size-fits-all" result. Shown also are perforations in a continuoussupport sheet for use in detaching leads used in forming an Einthoventriangle equivalent Left Arm, Right Arm and Left Leg pattern.

FIG. 7c shows a bioelectric interface configured for use with a twelvelead (ECG) system. Shown are groups of electrodes made of a plurality ofelectrode elements configured as shown in FIG. 5a, which serve to allowhigh frequency investigation and mapping. Shown also are perforations ina continuous support sheet for use in detaching leads used in forming anEinthoven triangle equivalent Left Arm, Right Arm and Left Leg pattern.

FIG. 7d shows a bioelectric interface configured for use with a twelvelead (ECG) system. Indicated are electrodes positioned beneath paddlesof a defibrillating system.

DETAILED DESCRIPTION

Turning now to the Drawings, there is shown in FIG. 1a a sideelevational cross-sectional view of a single electrode (E) in abioelectric interface (1) system comprising a Support Sheet (SUP) and anadhesive material (AS). Note that the electrode (E) is "sandwiched"between the Support Sheet (SUP) and adhesive material (AS). This is atypical arrangement, but where an adhesive material can providesufficient spatial positioning integrity it is to be understood that theSupport Sheet (SUP) can become unnecessary. FIG. 1b shows a sideelevational view of two electrodes situated on an adhesive sheet inessentially fixed relative positions with respect to one another.

FIG. 2 shows a bioelectric interface system (2) comprised of twoelectrodes (E1) and (E2) looking from the surface thereof upon which ispresent an adhesive material (AS), (ie. that surface which will contacta subject's skin in practice). Note that a "slit" (S) is shown aspresent between said electrodes (E1) and (E2). In the case where theadhesive material is made of an electrically isotropic material, (eg.commercially available hydropolymers in sheet form for instance), it hasbeen found that providing a slit (S) between two electrodes (E1) and(E2) effects essentially electrically anisotropic properties thereto.That is, a lower specific impedance will be measured from an electrodethrough the adhesive material than between two electrodes. In the casethat an adhesive material provides such anisotropic electrical specificimpedance properties, said slit (S) typically becomes unnecessary. It isnoted that the reason the adhesive material should provide anisotropicelectrical properties is that in an (ECG) setting, for instance, if theadhesive material is electrically isotropic, signals which should bepresent in one electrode in a bioelectric interface, will to some extentbe present in other electrodes as well, as a result of lateral currentflow through said adhesive material, and many prior multiple electrodesystems therefore, enter an artifact to (ECG) data as a result. As well,adhesive material electrical anisotropicity allows use of higherresolution electrode geometry, (discussed supra) because lateral currentflow is limited.

It will be noted that the adhesive material (AS) in FIG. 2 is notcompletely bisected by the slit (S). This is a preferred, but notlimiting practice, because complete electrode isolation is not alwaysoptimum. For instance, in (ECG) system settings it is common to inject anoise compensating signal to a Right Leg electrode via a driver circuit,which signal is to be imposed upon all electrodes. This practice is wellknown by practitioners in the (ECG) field, with noise compensatingcurrent flow normally being through a subject's skin, but it has beenfound that allowing some electrical path through the adhesive materialdoes not noticeably degrade acquired (ECG) data. With that thought inmind it is noted that a goal of the present invention is to provide avery firm affixation to a subject's body such that spatial separationbetween electrodes is maintained constant and such that good electricalcontact between electrodes and a subject's skin is effected, via saidadhesive material. Hence, the more surface area of the present inventionbioelectric interface upon which the adhesive material remains present,the better.

FIG. 3a shows a present invention system for providing electricallyanisotropic specific impedance in an "adhesive sheet". Shown is anelectrically non-conductive "Scrim" (SM) present in a form whichprovides numerous channel regions, said channel regions being filledwith electrically isotropic conductive adhesive material (A).

Turning now to FIGS. 4a and 4b, there are shown preferred shapes (E3)and (E4) for electrodes. Note that there are regions of said electrodeswhich will tend to project into an adhesive material (AS) placed incontact therewith. The effect of said projection is to provide athinning of the adhesive material (AS) and effect an electricallyanisotropic character to the adhesive material (AS) as viewed in crosssection. That is, electrical impedance from an electrode (E3) or (E4)through said adhesive material (AS) will be caused to be less than thatbetween electrodes (E3) and (E4) through said adhesive material (AS),because of a thinning effect at the projecting edges of said electrodes.FIG. 4c demonstrates the adhesive material (AS) thinning effect. Anyelectrode shape effecting a similar effect is to be consideredequivalent. FIG. 4c also shows the presence of external deviceelectrical connector means (EC).

FIG. 5a shows an example of a multi-element electrode (E5) with a"Bulls-eye" geometry. As described in the Disclosure of the InventionSection of herein, use of said multiple element electrodes allowsinvestigation of high frequency components in (ECG) signals, and allowsbetter spatial resolution of the sources of monitored (ECG) signals. (Itis to be understood that the "Bulls-eye" shape is an example of amulti-element electrode, and that any functionally similar multi-elementelectrode configuration is to be considered as included within the term"Bulls-eye"). The underlying distinction between multi-elementelectrodes and single element electrodes being that multiple singleelement electrodes typically utilize a single common electrode as areference, whereas multi-element electrodes provide their own referencepoint. It will be appreciated that electrical anisotropicity can becomevery important in view of the higher resolution capability of"Bulls-eye" electrodes, when signals are being monitored from closelypositioned points of, for instance a human heart muscle. That is,greater resolution capability is of no consequence if the signalreaching a sensing electrode is effected by lateral current flow throughan attached adhesive material, which signal was originated by a distalsource. FIG. 5b shows a plurality of "Button" electrode elements (B6),(B7), (B8), (B9), and (B10) which comprise an electrode (E6). Such anarrangement is beneficially utilized in a present invention BioelectricInterface meant for use in Defibrillation. The well known "Edge" effectwhich results in uneven current distribution over the region of anelectrode can be reduced by such a configuration.

FIG. 6a shows a partial human torso with RA, LA and LL electrodes placedon the limbs. Also shown is an Einthoven triangle Wilson Common Terminal(WCT) formed by attaching resistors to said RA, LA and LL electrodes,which resistors have a common central connection so as to form a "Y"circuit.

FIG. 6b shows a partial human torso with RA, LA and LL electrodes placedon the chest as is effected by the present invention BioelectricInterface (3). Also shown is an Einthoven equivalent frontal I II, IIIlead triangle, Wilson Common Terminal (WCT) formed by attachingresistors (r1), (r2) and (r3) to said RA, LA and LL electrodes, whichresistors have a common central connection so as to form a "Y" circuit.

It is the result of the present invention that voltages which appear atWilson Common Terminals shown in FIGS. 6a and 6b, each with respect toground, are essentially equivalent, if the present invention RA, LA andLL electrodes are appropriately positioned within the FIG. 6bdemonstrated bioelectric interface. A method of accomplishing this canbe aided by causing at least one of the RA, LA and LL electrodes to becomprised of a plurality of electrically independent electrode elements,(as demonstrated in FIG. 7b). A user can, manually or via automation,optimally select an element in each RA, LA and LL electrode. Asdescribed in the Disclosure of the Invention Section, appropriateplacement of the present invention RA, LA and LL electrodes in a presentinvention biointerface as applied to a subject, is achieved when avoltage present at a Wilson Common Terminal as shown in FIG. 6b, isessentially the same as the voltage present at a Wilson Common Terminalas shown in FIG. 6a within some user selected voltage deviation range,(eg. less than one (1.0) millivolt).

Turning now to FIG. 7a there is shown an approximately "actual size"typical present invention bioelectric interface system (3) withelectrodes present therein and appropriately spatially distributed andpositioned for use with a twelve lead (ECG) system. FIG. 7a shows thesurface of the present invention bioelectric interface (3) opposite tothat upon which is typically present an adhesive material which contactsa subject's skin in use. In use the bioelectric interface system (3)will typically be placed upon a subject's chest with the variousprecordial V1-V6 electrodes, and electrode groups, placed as follows:

electrode V1--in the region of the fourth intercostal space at the rightsternal border.

electrode V2--in the region of the fourth intercostal space at the leftsternal border;

electrode V4--in the region of the fifth intercostal space at the leftmid-clavicular line;

electrode V3--in the region half way between electrodes V2 and V4;

electrode V5--in the region of the fifth intercostal space at the leftanterior axillary line; and

electrode V6--in the region of the fifth intercostal space at the leftmid-axillary line.

Note that electrodes V4, V5 and V6 are each shown as a group ofelectrode elements. The present invention provides for any of theelectrodes V1-V6 and any other electrodes which might be present, to bepresent as a group thereof. The reason for this is that the presentinvention bioelectric interface is truely a "single size fits allsystem". That is, even though subject's body sizes vary greatly one toanother, the present invention can be applied to essentially anynon-deformed subject and an electrode within a group of electrodes inthe region of an appropriate location will be found to be properlypositioned for use, within an error which exists even if individualelectrodes are utilized, (said error originating from improperapplication of a single electrode). It is emphasized that while only V4,V5 and V6 precordial electrodes are shown as groups of electrodeelements in FIG. 7a, any electrode shown, or any other configuration ofelectrode elements utilized, can be present as a group of electrodes asnecessary to effect the "one-size-fits-all" feature of the presentinvention bioelectric interface system. The reason that FIG. 7a showselectrodes V1, V2 and V6 as single electrodes and electrodes V4, V5 andV6 as shown as groups of electrode elements is that, in practice,application of the present invention bioelectric interface system to asubject's body will proceed in a manner that typically assuresappropriate positioning of electrodes V1, V2 and V3 on a subject'schest. The remaining electrodes will then make contact with thesubject's body at locations based upon the size and shape of thebioelectric interface (3), which for any specific electrode might ormight not be at the generally accepted locations recited infra. Where agroup of electrodes is present, however, it should be appreciated thatone of the electrodes in the group will be found to be moreappropriately positioned than the others of the group. It is also notedthat where groups of electrodes are present, unused electrodes in agroup can be utilized as, for instance, electrodes to effect cardiacpacing. As well, if one electrode in a group becomes inoperable, anothercan be substituted and still allow acquisition of reasonable (ECG) data.(See FIGS. 7b and 7c for other non-limiting examples). Also, multipleelectrodes can be combined in a parallel configuration to allow greatercurrent carrying capability during, for instance, defibrillationprocedures.

Shown also in FIG. 7a are also the Right Arm (RA), Left Leg (LL) andLeft Arm (LA) electrodes, positioned as appropriate for use as anEinthoven triangle equivalent configuration pattern, and for use asRight Arm (RA), Left Leg (LL) and Left Arm (LA) equivalent electrodes inthe present invention bioelectric interface. Said electrodes arepositioned as:

electrode (RA)--in the general region of the second intercostal space tothe right of the sternum;

electrode (LA)--in the general region of the left fourth intercostalspace at the mid-axillary line; and

electrode (LL)--in the general region of the inferior costal margin atthe right or left mid-clavicular line.

(Note, multiple electrodes designated Right Leg (RL) are also present.As alluded to above, the Right Leg (RL) electrode in (ECG) settings istypically utilized to inject an out-of-phase noise compensating signal,which can be functionally applied to many electrodes. It has beendetermined that said noise compensating signal can be injected at anyessentially any location on the present invention bioelectric interfacewithout degradation of the results).

Also note that slits (S) in an electrically isotropic adhesive materialare shown in broken lines. As viewed, said adhesive material would bepresent on a lower surface of the shown present invention bioelectricinterface (3), hence are shown as viewed through the adhesive materialand indicated Support Sheet (SUP). Said slits (S) will be lessnecessary, and probably unnecessary, where an adhesive materialconstructed from an inherently electrically anisotropic material, suchas demonstrated by FIGS. 3a and 3b, is utilized. In such systems thescrim (SM) can provide structural integrity, while the presentelectrically conductive adhesive can provide sufficient adhesive contactand electrical conductivity.

Also note that FIG. 7a shows one of the V6 electrodes as a "Bulls-eye"electrode with a central Button (B1) and outer annular ring (B2)present. Again, this is demonstrative, and in effect all electrodescould be of a multi-element construction. The conductive polymer willtypically, though not necessarily, be discontinuous between the elementof a multi-element electrode. Note than the central Button (B1) canstill serve as a standard Button electrode. In use, one could alsointerconnect the V6 (B1) and (B2) elements, or all the electrodes in agroup, (for instance, if it became necessary to defibrillate a subjectwhile a present invention bioelectric interface is in place).Conventional practice would require removal of any such electrodeproviding system. However, where the present invention bioelectricinterface (3) is present, a defibrillation paddle could be positioned toeffectively form a single electrode from electrodes in the V4, V5 and V6groups. (Note said defibrillation paddle could contact external contactmeans (EC) such as shown in FIG. 4c). A second defibrillation paddlecould likewise be simultaneously applied to the V1, V2 and V3electrodes, or group of electrodes should alternatives be present at V1,V2 and V3 electrode locations. (See FIG. 7d for indication ofDefibrillation Paddles in use).

Again, FIG. 7a provides a non-limiting example of a BioelectricInterface (3) of the present invention. The present invention is,however, in the combination of the various disclosed elements thereof,in their various forms, as well as in electrode positioning.

Continuing, FIG. 7b shows a present invention Bioelectric Interface (3)with electrodes consisting of a FIG. 5b electrode element arrangementpresent at all V1, V2, V3, V4, V5 and V6 locations in the Support Sheet(SUP). RA, LA and LL electrodes are also shown to comprise multipleelectrode elements. As in FIG. 7a, the Bioelectric Interface is viewedfrom the non-subject contacting side, and indications of the presence,and positioning of electrodes electrically accessible from both theshown, and subject contacting sides is present. The dotted linessurrounding each of said V1, V2, V3, V4, V5 and V6 locations is toindicate that the FIG. 5b electrode element arrangement is to be takenin combination as an electrode. Also note that FIG. 7b showsPerforations (P) present in the Support Sheet (SUP) at electrode RA, LA,and LL, (eg. Right Arm, Left Arm and Left Leg) locations. SaidPerforations (P) allow easy removal of the RA, LA, and LL electrodeswhen it is desired to deploy and place said electrodes at conventionalsubject limb locations in use.

FIG. 7c shows a present invention Bioelectric Interface (3) with FIG. 5aBulls-eye electrodes present at V1, V2, V3, V4, V5 and V6 locations inthe Support Sheet (SUP). As in FIGS. 7a and 7b, the BioelectricInterface is viewed from the non-subject contacting side, andindications of the presence, and positioning of electrodes electricallyaccessible from both the shown, and subject contacting sides is present.Also note that FIG. 7c, as did FIG. 7b, shows Perforations (P) presentin the Support Sheet (SUP) at electrode RA, LA, and LL (eg. Right Arm,Left Arm and Left Leg) locations. Said Perforations (P) allow easyremoval of the RA, LA, and LL electrodes when it is desired to deployand place said electrodes at, for instance, conventional limb locationsin use.

FIG. 7d shows a present invention Bioelectric Interface (3) with simplesingle Button electrodes present at V1, V2, V3, V4, V5 and V6 locationsin the Support Sheet (SUP). As in FIGS. 7a, 7b and 7c, the BioelectricInterface is viewed from the non-subject contacting side, andindications of the presence, and positioning of electrodes electricallyaccessible from both the shown, and subject contacting sides is present.Also shown are outline representations of First (DF1) and Second (DF2)Defibrillation Paddles placed over the RA, LA, LL, V1, V2, V3, V4, V5and V6 electrodes of the present invention Bioelectric Interface (3), assaid First (DF1) and Second (DF2) Defibrillation Paddles would bepositioned in use. Note that First (PD1) Defibrillation Paddleelectrically contacts electrodes RA, V1, V2, and V3, while Second (DF2)Defibrillation Paddle electrically contacts electrodes LA, LL, V4, V5,and V6. The multiple points of supply of electrical energy to the bodyof a subject wearing the present invention Bioelectric Interface (3)serves to reduce uneven current flow caused by electrode "Edge" effect.It should be appreciated that were First (DF1) and Second (DF2)Defibrillation Paddles shown applied to FIGS. 7b or 7c, even moreseparate electrode elements would be contacted, and the "Edge" effectwould be even more reduced.

As a general comment regarding FIGS. 7a, 7b, 7c and 7d, the electrodesare shown positioned in each Bioelectric Interface (3), as viewed fromthe non-subject contacting side thereof. FIG. 4c demonstrates thetypically only an external device electrical connector means (EC) isvisible as so viewed, with a typically larger electrode area present onthe subject contacting side. Hence, FIGS. 7a, 7b, 7c and 7d should beviewed as demonstrating the positioning of electrodes, and elementswhich comprise them, in a present invention Bioelectric Interface,rather than being accurate representations of the size of saidelectrodes, as viewed.

As another general comment, it is to be appreciated that the presentinvention bioelectric interface system provides a means by which manyelectrodes can be applied to a subject by a simple, error limitingprocedure. As it is generally accepted that improper application ofelectrodes is the most common reason for faulted (ECG) data acquisition,this is significant. As well, the present invention bioelectricinterface provides a rather significant body contact surface area, saidsurface area being, typically, essentially covered with an adhesivematerial. This serves to ensure that electrodes, once applied to asubject, will not vary from the positions in which they are applied, andshould not vary with respect to one another. It is known that relativemotion between electrodes accounts for production of noise in acquired(ECG) data. The present invention greatly limits problems associatedwith noise generated by this effect. In fact, it is generally possiblyto perform cardio-pulmonary-resuscitation on subjects wearing thepresent invention bioelectric interface while continuing to acquire(ECG) data. It is also mentioned that when the adhesive material is ahydropolymer, subject discomfort is minimized, and moisture resultingfrom sweating etc. actually serves to improve the adhesion properties.

While not shown, it is possible to form arrays of electrodes in apresent invention bioelectric interface, for use in cardiac mapping. Insuch arrays, electrode arrangement is typically rectangular with, forinstance, sixteen, twenty-four, thirty-six, sixty-four etc. electrodespresent. The electrodes present can be of Button or Bulls-eye geometry,or, in other embodiments of the present invention, can be of anyfunctional geometrical shape. It is also noted that it is possible toaffix alternative embodiments of the present invention bioelectricinterface to the back of a subject as well as to the chest thereof.

It is also noted that primary evidence that a Wilson Common Terminal(WCT) Voltage produced utilizing a present invention BioelectricInterface is equivalent to that produced when conventionally placed limbleads are utilized, is essential equivalence of monitored ECG leadoutputs from both said systems. In that light it is to be understoodthat a conventional Wilson Common Terminal is constructed utilizingresistors of equal value, (eg. 10,000 ohms each). Again refering toFIGS. 6a and 6b, this is equivalent to considering Resistors (r1), (r2)and (r3) to be of equivalent values. Where this is the case, placementof the Right Arm (RA), Left Arm (LA) and Left Leg (LL) electrodes alone,in a FIG. 6b setting, provides for realizing a voltage at the FIG. 6bWilson Common Terminal (WCT) which is in a desired relationship to thatpresent at the Wilson Common Terminal (WCT) formed utilizing electrodespositioned on limbs, as shown in FIG. 6a. However, it should beappreciated that if resistors (r1), (r2) and (r3) are variable, thenadjusting their values can also have an effect on the voltage whichappears at a Wilson Common Terminal (WCT). The present inventionprovides for use of variable (r1) and/or (r2) and/or (r3) resistor(s)such that in use, adjustment of one or more of said variable (r1) and/or(r2) and/or (r3) resistor(s) allows "setting" a voltage at the WilsonCommon Terminal (WCT) to essentially any value at, or anywhere between,the voltages present at any of the Right Arm (RA), Left Arm (LA) andLeft Leg (LL) electrodes. Thus, the present invention can include as aMethod of Use step, adjustment of the values of the resistors which formthe Wilson Common Terminal (WCT), after a FIG. 6b Bioelectric Interface(3) is placed upon a subject's chest. (Note that Operational Amplifierswith adjustable gain can be utilized in place of the described variableresistors and are to be considered functionally equivalent and withinthe scope of the terminology "variable resistor". Op-Amps beneficiallyprovide high input impedance.)

It will be apparent to those skilled in the art that some redundancyexists in any Einthoven-like lead system which lies largely in a singlesubject body plane, such as the frontal plane. Some minor efficienciesmight be achieved, at the expense of redundance, if for example, twomutually perpendicular leads were created and used exclusively to definethe frontal plane in electrocardiology. Furthermore, othermathematically derived leads are commonly employed to provide additionalinformation, (eg "augmented" frontal plane leads). However, it is to beunderstood that new heart related information can not be created simplyby the mathematical manipulation of redundant information. Therefore,where appropriate, the Claims are to be interpreted to includemathematically equivalent lead placement systems. In particular, thelanguage, "generally in the region of" should be interpretedsufficiently broadly to include both an Einthoven equivalent triangleand an orthogonal lead configuration formed by a shifting of a leadposition, which identified lead configurations provide mathematicallyessentially equivalent information.

Finally, it is noted that the terminology "Wilson Common Terminal" hasbeen used throughout this Disclosure, whereas many references utilizethe terminology "Wilson Central Terminal". The term "Common" is used toimply application in an instrumentation setting, but for most purposesit can be read as "Central" without loss of accuracy.

Having hereby disclosed the subject matter of the present invention, itshould be obvious that many modifications, substitutions, and variationsof the present teachings are possible in view of the teachings. It istherefore to be understood that the present invention may be practicedother than as specifically described, and should be limited in breadthand scope only by the Claims.

I claim:
 1. A bioelectric interface comprising a support sheet in functional combination with at least three (3) spatially separated electrocardiogram system electrodes, each of said at least three (3) spatially separated electrocardiogram system electrodes being of a construction selected from the group consisting of:a single electrical electrode element; and a group of electrically independent electrode elements;each of said spatially separated electrocardiogram system electrodes being affixed to said support sheet in a manner such that the relative positions of said electrocardiogram system electrodes with respect to one another are essentially fixed therewithin, three (3) of said at least three (3) electrocardiogram system electrodes being configured in an RA, LA, LL electrocardiogram system electrode pattern, said RA, LA and LL electrodes forming, when mounted to a subject's chest in use, an Einthoven frontal lead triangle with an equivalent I, II, III lead pattern presenting with a voltage with respect to ground at a Wilson common terminal formed from "Y" connected resistors from each of said RA, LA and LL electrodes, said resistors each being selected from the group consisting of: fixed; and variable;said voltage with respect to ground being within a selected range of deviation from a voltage with respect to ground which would present at a Wilson common terminal formed using conventional subject limb positioning of RA, LA and LL electrodes, said selected range of voltage deviation being selected from the group consisting of: less than one (1.0) milivolt; one (1.0) milivolt; and greater than one (1.0) milivolt;thereby enabling familiar ECG data acquisition from ECG leads which reference to said Wilson common terminal; said bioelectric interface further comprising perforations in said support sheet which allow easy detachment and deployment of said Einthoven triangle forming RA, LA and LL electrodes, so that said Einthoven triangle forming RA, LA, and LL electrodes are, in use, each positionable at locations selected from the group consisting of: in contact with a subject's chest; and in conventional Einthoven triangle forming subject limb positions.
 2. A bioelectric interface as in claim 1 which further comprises an electrocardiogram system RL electrode.
 3. A bioelectric interface as in claim 2 which further comprises perforations in said support sheet which allow easy detachment and deployment of said electrocardiogram RL electrode thereby enabling, in use, positioning thereof at a location selected from the group consisting of:in contact with a subject's chest; and in conventional subject limb position.
 4. A bioelectric interface as in claim 1 in which said Einthoven triangle forming RA, LA AND LL electrodes are, as applied to a subject's chest during use, situated as follows:electrode RA being generally in the region of the second intercostal space to the right of the sternum; electrode LA being generally in the region of the left fourth intercostal space in the mid-axillary line; electrode LL being generally in the region of the inferior costal margin in the left mid-clavicular line.
 5. A bioelectric interface as in claim 1, in which the support sheet is at least partially covered with an adhesive material on a side thereof which contacts a subject in use, which adhesive material presents with electrical conductive properties selected from the group consisting of:isotropic electrical conductive properties; and anisotropic electrical conductive properties such that regional specific impedance through said adhesive material is less that in a laterally oriented direction therealong.
 6. A bioelectric interface as in claim 1, in which the support sheet is at least partially covered with an adhesive material on a side thereof which contacts a subject in use, the electrical conductive properties of said adhesive material being regionally anisotropic, said anisotropic electrical conductive properties of said adhesive material resulting from the presence of an electrically nonconductive scrim patterned therein so as to form channel regions of electrically conductive adhesive material through said adhesive material bordered by said scrim material, such that adhesive material in one channel region does not contact that in other regions.
 7. A bioelectric interface as in claim 1, in which the support sheet is at least partially covered with an adhesive material on a side thereof which contacts a subject in use, the electrical conductive properties of said adhesive material being regionally anisotropic, said anisotropic electrical conductive properties of the adhesive material resulting from the presence of slits formed therein.
 8. A bioelectric interface as in claim 1, in which the support sheet is at least partially covered with an adhesive material on a side thereof which contacts a subject in use, said adhesive material being a hydropolymer with electrical conductive properties selected from the group consisting of:isotropic electrical conductive properties; and anisotropic electrical conductive properties such that regional specific impedance through said adhesive material is less that in a laterally oriented direction therealong.
 9. A bioelectric interface as in claim 8, in which the hydropolymer adhesive material covers essentially the entire side thereof which contacts a subject in use.
 10. A bioelectric interface as in claim 1, in which at least one of said spatially separated electrocardiogram system electrodes is of a construction consisting of a group of electrically independent electrode elements.
 11. A bioelectric interface as in claim 10, in which said electrically independent electrode elements are configured in a pattern selected from the group consisting of:a Bulls-eye pattern; and multiple button shaped electrode elements.
 12. A method of providing an Einthoven triangle equivalent RA, LA, LL pattern of electrodes on the chest of a subject comprising the steps of:a. providing a bioelectric interface comprising a support sheet in functional combination with at least three (3) spatially separated electrocardiogram system electrodes, at least one (1) of said at least three (3) spatially separated electrocardiogram system electrodes being of a construction consisting of a group of electrically independent electrode elements, each of said spatially separated electrocardiogram system electrodes being affixed to said support sheet in a manner such the relative positions of said electrocardiogram system electrodes with respect to one another are essentially fixed therewithin, three (3) of said at least three (3) electrocardiogram system electrodes being configured in an RA, LA, LL electrocardiogram system electrode pattern, said RA, LA and LL electrodes forming, in use, an Einthoven frontal lead triangle with an equivalent I, II, III lead pattern presenting with a voltage with respect to ground at a Wilson common terminal formed from "Y" connected resistors from each of said RA, LA and LL electrodes, said resistors each being selected from the group consisting of: fixed; and variable;said voltage with respect to ground being within a selected range of deviation from a voltage with respect to ground which would be present at a Wilson common terminal formed using conventional subject limb positioning of RA, LA and LL electrodes, said selected range of voltage deviation being selected from the group consisting of: less than one (1.0) milivolt; one (1.0) milivolt; and greater than one (1.0) milivolt;thereby enabling familiar ECG data acquisition from ECG leads which reference to said Wilson common terminal; b. applying said bioelectric interface to a subject; c. selecting at least one electrically independent element in each of said at least one electrocardiogram system RA, LA and LL electrode(s) consisting of a group of electrically independent electrode elements to constitute the electrode of which it is an electrically independent element; d. connecting said electrocardiogram system RA, LA and LL electrodes to appropriate inputs of an electrocardiogram system.
 13. A method of providing an Einthoven triangle equivalent RA, LA, LL pattern of electrodes on the chest of a subject as in claim 12, which further comprises the step of performing a procedure selected from the group consisting of;a. cardio-pulmonary resuscitation b. cardiac defibrillation; c. cardiac pacing; d. electro surgery; e. electro-ablation; and f. impedance cardiography;on said subject without removing said bioelectric interface.
 14. A bioelectric interface comprising a support sheet in functional combination with at least nine (9) spatially separated electrocardiogram system electrodes, each of said at least nine (9) spatially separated electrocardiogram system electrodes being of a construction selected from a group consisting of:a single electrical electrode element; and a group of electrically independent electrode elements;each of said spatially separated electrocardiogram system electrodes being affixed to said support sheet in a manner such that the relative positions of said electrocardiogram system electrodes with respect to one another are essentially fixed therewithin, nine (9) of said at least nine (9) electrocardiogram system electrodes being configured in an RA, LA, LL, V1, V2, V3, V4, V5, V6 electrocardiogram system electrode pattern, such that said nine (9) electrocardiogram system electrodes are applied to a subject's chest during use as follows: electrode V1 in the region of the fourth intercostal space at the right sternal border; electrode V2 in the region of the fourth intercostal space at the left sternal border; electrode V4 in the region of the fifth intercostal space at the left mid-clavicular line; electrode V3 in the region of the midpoint between electrode groups V2 and V4; electrode V5 in the region of the fifth intercostal space in the left anterior axillary line; and electrode V6 in the region of the fifth intercostal space in the left mid-axillary line; electrode RA being generally in the region of the second intercostal space to the right of the sternum; electrode LA being generally in the region of the left fourth intercostal space in the mid-axillary line; electrode LL being generally in the region of the inferior costal margin in the left mid-clavicular line;said electrodes RA, LA and LL being positioned so as to form, in use, an Einthoven frontal lead triangle with an equivalent I, II, III lead pattern presenting with a voltage with respect to ground at a Wilson common terminal formed from "Y" connected resistors from each of said RA, LA and LL electrodes, said resistors each being selected from the group consisting of: fixed; and variable;said voltage with respect to ground being within a selected range of deviation from a voltage respect to ground which would present at a Wilson common terminal formed using conventional subject limb positioning of RA, LA and LL electrodes, said selected range of voltage deviation being selected from the group consisting of: less than one (1.0) milivolt; one (1.0) milivolt; and greater than one (1.0) milivolt);thereby enabling familiar ECG data acquisition from ECG leads which reference to said Wilson common terminal; said bioelectric interface further comprising perforations in said support sheet which allow easy detachment and deployment of said Einthoven triangle forming RA, LA and LL electrodes therefrom so that said Einthoven triangle forming RA, LA, and LL electrodes are, in use, positionable at locations selected from the group consisting of: in contact with a subject's chest; and in conventional Einthoven triangle subject limb positions.
 15. A bioelectric interface as in claim 14 which further comprises an electrocardiogram system RL electrode.
 16. A bioelectric interface as in claim 15 which further comprises perforations in said support sheet which allow easy detachment and deployment of said electrocardiogram RL electrode thereby enabling, in use, positioning thereof at a location selected from the group consisting of:in contact with a subject's chest; and in conventional subject limb position.
 17. A bioelectric interface as in claim 14, in which the support sheet is at least partially covered with an adhesive material on a side thereof which contacts a subject in use, which adhesive material presents with electrical conductive properties selected from the group consisting of:isotropic electrical conductive properties; and anisotropic electrical conductive properties such that the regional specific impedance through said adhesive material is less than in a laterally oriented dimension direction therealong.
 18. A bioelectric interface as in claim 14 in which the support sheet is at least partially covered with an adhesive material on a side thereof which contacts a subject in use, the electrical conductive properties of said adhesive material being anisotropic, said anisotropic electrical conductive properties of said adhesive material resulting from the presence of an electrically nonconductive scrim patterned therein so as to form channel regions of electrically conductive adhesive material through said adhesive material bordered by said scrim material, such that adhesive material in one channel region does not contact that in other regions.
 19. A bioelectric interface as in claim 14, in which the support sheet is at least partially covered with an adhesive material on a side thereof which contacts a subject in use, the electrical conductive properties of said adhesive material being anisotropic, said anisotropic electrical conductive properties of the adhesive material resulting from the presence of slits formed therein.
 20. A bioelectric interface as in claim 14, in which the support sheet is at least partially covered with an adhesive material on a side thereof which contacts a subject in use, said adhesive material being a hydropolymer with isotropic electrical conductive properties.
 21. A bioelectric interface as in claim 20, in which the hydropolymer adhesive material covers essentially the entire surface of said support sheet on the side thereof which contacts a subject in use.
 22. A bioelectric interface as in claim 14 in which the support sheet is at least partially covered with an adhesive material on a side thereof which contacts a subject in use, said adhesive material being a hydropolymer with regional anisotropic electrical conductive properties.
 23. A bioelectric interface as in claim 22, in which the hydropolymer adhesive material covers essentially the entire surface of said support sheet on the side thereof which contacts a subject in use.
 24. A bioelectric interface as in claim 14, in which at least one of said spatially separated electrocardiogram system electrodes is of a construction consisting of a group of electrically independent electrode elements.
 25. A bioelectric interface as in claim 24, in which said electrically independent electrode elements are configured in a pattern selected from the group consisting of:a Bulls-eye pattern; and multiple button shaped electrode elements.
 26. A method of acquiring electrocardiographic data comprising the steps of:a. providing a bioelectric interface comprising a support sheet in functional combination with at least nine (9) spatially separated electrocardiogram system electrodes, each of said at least nine (9) spatially separated electrocardiogram system electrodes being of a construction selected from a group consisting of: a single electrical electrode element; and a group of electrically independent electrode elements;each of said spatially separated electrocardiogram system electrodes being affixed to said support sheet in a manner such the relative positions of said electrocardiogram system electrodes with respect to one another are essentially fixed therewithin, nine (9) of said at least nine (9) electrocardiogram system electrodes being configured in an RA, LA, LL, V1, V2, V3, V4, V5, V6 electrocardiogram system electrode pattern, such that said nine (9) electrocardiogram system electrodes are applied to a subject's chest during use as follows: electrode V1 in the region of the fourth intercostal space at the right sternal border; electrode V2 in the region of the fourth intercostal space at the left sternal border; electrode V4 in the region of the fifth intercostal space at the left mid-clavicular line; electrode V3 in the region of the midpoint between electrode groups V2 and V4; electrode V5 in the region of the fifth intercostal space in the left anterior axillary line; and electrode V6 in the region of the fifth intercostal space in the left mid-axillary line; and said electrodes RA, LA and LL being positioned so as to form, in use, an Einthoven frontal lead triangle with an equivalent I, II, III lead pattern presenting with a voltage with respect to ground at a Wilson common terminal formed from "Y" connected resistors from each of said RA, LA and LL electrodes, at least one of said resistors from each of said RA, LA and LL electrodes being variable;said voltage with respect to ground being within a selected range of deviation from a voltage respect to ground which would present at a Wilson common terminal formed using conventional subject limb positioning of RA, LA and LL electrodes, said selected range of voltage deviation being selected from the group consisting of: less than one (1.0) milivolt; one (1.0) milivolt; and greater than one (1.0) milivolt;thereby enabling familiar ECG data acquisition from ECG leads which reference to said Wilson common terminal; b. affixing said bioelectric interface to a subject and causing electrodes therein to be electrically attached to an electrocardiographic system; c. adjusting the resistance value of at least one of said at least one Wilson common terminal forming "Y" connected resistors, from each of said RA, LA and LL electrodes, which is variable, to place the Wilson common terminal voltage within a selected range of deviation from a voltage which would present at a Wilson common terminal formed using conventional subject limb positioning of RA, LA and LL electrodes, said range being selected from the group consisting of: less than one (1.0) milivolt; one (1.0) milivolt; and greater than one (1.0) milivolt);such that familiar electrocardiographic data from ECG leads which reference to said Wilson common terminal, is obtained.
 27. A method of acquiring electrocardiographic data as in claim 26, in which the step of providing a bioelectric interface includes providing perforation(s) in said support sheet such that at least one of said three electrodes configured in an Einthoven frontal lead triangle equivalent RA, LA, and LL pattern can be easily removed therefrom; said method of acquiring electrocardiographic data further including the step of removing said at least one of said electrode(s) RA, LA and LL which are configured in an Einthoven frontal lead triangle equivalent LA, RA, LL pattern, and affixing it/them to conventional subject limb locations.
 28. A method of acquiring electrocardiographic data as in claim 26, in which the step of providing a bioelectric interface includes providing an adhesive material present over at least a portion of a side of said support sheet which contacts a subject in use.
 29. A method of acquiring electrocardiographic data as in claim 26, in which the step of providing said bioelectric interface comprises the step of causing at least some of said electrodes to comprise a group of electrically independent electrode elements configured in a pattern selected from the group consisting of:Bulls-eye pattern; and multiple button shaped electrode elements.
 30. A method of acquiring electrocardiographic data as in claim 26, which further comprises the step of performing a procedure selected from the group consisting of;a. cardio-pulmonary resuscitation b. cardiac defibrillation; c. cardiac pacing; d. electro surgery; e. electro-ablation; and f. impedance cardiography;on said subject without removing said bioelectric interface.
 31. A method of acquiring electrocardiographic data as in claim 26, which further comprises the step of performing cardiac defibrillation utilizing two conventional defibrillation paddles, in which a first conventional defibrillation paddle contacts at least two of said at least nine electrocardiogram system electrodes, and in which a second said conventional defibrillation paddles contacts at least two of said at least nine electrocardiogram system electrodes, said at least two electrodes contacted by said first conventional defibrillation paddle being different than and sread apart from said at least two electrodes contacted by said second conventional defibrillation paddle; with the result being that in use said electrodes contacted by said defibrillation paddles are caused to be pressed into firm contact with a subject and defibrillation pulse current delivered thereto with current distribution electrode edge effects being reduced.
 32. A bioelectric interface comprising a support sheet in functional combination with at least three (3) spatially separated electrocardiogram system electrodes, each of said at least three (3) spatially separated electrocardiogram system electrodes being of a construction selected from the group consisting of:a single electrical electrode element; and a group of electrically independent electrode elements;each of said spatially separated electrocardiogram system electrodes being affixed to said support sheet in a manner such that the relative positions of said electrocardiogram system electrodes with respect to one another are essentially fixed therewithin, three (3) of said at least three (3) electrocardiogram system electrodes being configured in an RA, LA, LL electrocardiogram system electrode pattern; which RA, LA and LL electrodes, when functionally combined with resistors from each thereof, which resistors are "Y" interconnected to provide a Wilson central terminal, form an Einthoven frontal lead triangle with an equivalent I, II, III lead pattern when mounted to a subject's chest; such that when mounted to a subject's chest in use a voltage with respect to ground developed at said Wilson central terminal is within a selected range of deviation from a voltage with respect to ground which would present at a Wilson central terminal formed using conventional subject limb positioning of said RA, LA and LL electrodes, said selected range of voltage deviation being selected from the group consisting of: less than one (1.0) milivolt; one (1.0) milivolt; and greater than one (1.0) milivolt;thereby enabling familiar ECG data acquisition from ECG leads which reference to said Wilson central terminal; said bioelectric interface further comprising perforation(s) in said support sheet which allow easy detachment and deployment of at least one of said Einthoven frontal lead triangle forming RA, LA and LL electrodes, so that said at least one of said Einthoven triangle forming RA, LA, and LL electrodes is/are, in use, positionable at locations selected from the group consisting of: in contact with a subject's chest; and in conventional Einthoven triangle forming subject limb positions.
 33. A bioelectric interface comprising a support sheet in functional combination with at least three (3) spatially separated electrocardiogram system electrodes as in claim 32, wherein at least one of said RA, LA and LL electrodes, when mounted to a subject's chest, is positioned as:said electrode RA being generally in the region of the second intercostal space to the right of the sternum; said electrode LA being generally in the region of the left fourth intercostal space in the mid-axillary line; said electrode LL being generally in the region of the inferior costal margin in the left mid-clavicular line.
 34. A bioelectric interface comprising a support sheet in functional combination with at least three (3) spatially separated electrocardiogram system electrodes, each of said at least three (3) spatially separated electrocardiogram system electrodes being of a construction selected from the group consisting of:a single electrical electrode element; and a group of electrically independent electrode elements;each of said spatially separated electrocardiogram system electrodes being affixed to said support sheet in a manner such that the relative positions of said electrocardiogram system electrodes with respect to one another are essentially fixed therewithin, three (3) of said at least three (3) electrocardiogram system electrodes being configured in an RA, LA, LL electrocardiogram system electrode pattern; which RA, LA and LL electrodes, when functionally combined with resistors from each thereof which are "Y" interconnected to provide a Wilson central terminal, form an Einthoven frontal lead triangle with an equivalent I, II, III lead pattern when mounted to a subject's chest in use; at least one of said resistors from said RA, LA and LL electrodes which are "Y" interconnected being variable such that, in use, said at least one resistor which is variable is adjusted to place the voltage which presents at the Wilson central terminal within a range of deviation from a voltage which would present at a Wilson central terminal formed using conventional subject limb positioning of RA, LA and LL electrodes, said range of deviation being selected from the group consisting of: less than one (1.0) milivolt; one (1.0) milivolt; and greater than one (1.0) milivolt;thereby enabling familiar ECG data acquisition from ECG leads which reference to said Wilson central terminal.
 35. A bioelectric interface comprising a support sheet in functional combination with at least three (3) spatially separated electrocardiogram system electrodes as in claim 34, said bioelectric interface further comprising perforation(s) in said support sheet which allow easy detachment and deployment of at least one of said Einthoven frontal lead triangle forming RA, LA and LL electrodes, so that said at least one of said Einthoven triangle forming RA, LA, and LL electrodes is/are, in use, positionable at locations selected from the group consisting of:in contact with a subject's chest; and in conventional Einthoven triangle forming subject limb positions. 